People with high rates of melanomas often report extensive use of sunscreen, according to Hacker. This has led to suggestions that while it protects against burning, sunscreen may not be useful against skin cancers.
“The only way to solve this is to get away from the epidemiology and look at the molecular basis,” Hacker says. She did this by taking samples of skin from 57 healthy individuals and exposing small patches to UV light, both with and without sunscreen, before taking a second biopsy.
Publishing in Pigment Cell and Melanoma Research, Hacker’s results were good news for the industry and public health campaigners. “As soon as our skin becomes sun-damaged, the p53 gene goes to work repairing that damage and thereby preventing skin cancer occurring,” Hacker says. “But over time, if skin is burnt regularly the p53 gene mutates and can no longer do the job it was intended for – it no longer repairs sun-damaged skin, and without this protection skin cancers are far more likely to occur.
“After 24 hours, where the sunscreen had been applied there were no DNA changes to the skin and no impact on the p53 gene,” Hacker says. Those who were not protected were not so lucky.
The study was done with a commercial sunscreen, and Hacker says the results may not be applicable to all products. However, she notes that the active ingredients of the most...
